the high-profile weight loss business in Beverly hills facing a new legal fight this morning, after its offices were raided by federal agents. ABC has covered complaints about the 1-800-get-thin programs in the past. And Brian Ross is back now with the latest developments. Reporter: Good morning, George. Federal agents are stepping up their investigation as you say one of the most high-profile and controversial weight loss clinics in the country. Five patients have died after lap-band surgery. Few doctors have made more money than these two Beverly hills brothers. With their business success and celebrity social life, they ended up on the cable TV program called "Dr. 90210." Now, they're under investigation, as founders of the widely advertised 1-800-get-thin weight loss business. As first reported by "The los Angeles times" their offices and their mother's home was raided by federal agents Thursday, as part of an investigation by the FBI, irs and the fda for potential health care fraud, money laundering and other federal crimes. The once ever-present advertising offered an easy one-hour way to lose weight, with a lap-band procedure to constrict the stomach. I tried every diet out there. Reporter: Done right, the lap-band procedure is a safe technique. But relatives of five patients who died after surgery at the brothers' clinics in los Angeles, say they were the victims of substandard care and negligent doctors. Is she breathing? No. Reporter: Carla died on the operating table. Laura suffered a lacerated liver. They're making this seem so easy, so easy. Reporter: Dr. Amini, Brian Ross the doctors would not talk with us when we first reported on them two years ago. But their lawyers say there are always great risks in dealing with obese patients. And that their clinics are professionally accredited and meet the highest standards. In testimony, one doctor who worked at the clinic said he was told by one of the brothers not to worry about any lawsuits over patient deaths because they're making so much money, they could easily afford any judgment against them. The brothers called that doctor a liar. This is an ongoing important case. Brian, thanks.

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